This invention relates generally to machines and systems for use in cleaning upholstery, such as carpets, draperies, furniture coverings, and the like. More particularly, this invention relates to an improved cleaning system and related machine designed for relatively quick and simple purge or flush removal of a selected cleaning solution from system components, thereby facilitating periodic use of different cleaning solutions which may be incompatible with each other.
Upholstery cleaning systems and related equipment components are, in general terms, relatively well-known in the art. Such systems commonly include a solution tank for receiving a supply of a selected cleaning solution, in combination with a pump and related flow lines for delivering the cleaning solution to an appropriate cleaning tool. The cleaning tool is normally designed for manual manipulation over a selected upholstery item or items to be cleaned. In this regard, the cleaning action provided by the solution is often enhanced by preheating and/or pressurizing the solution for delivery to the upholstery item, and/or by the use of brush or vibratory elements on the cleaning tool. Moreover, in some systems, the cleaning solution is delivered to the tool in a recirculation flow such that a portion of the solution is recycled on a continuous basis to the solution tank. At the conclusion of a cleaning procedure, a vacuum unit is typically employed to vacuum excess fluid and entrained debris from the upholstery. These equipment components are often provided in a convenient portable form carried on a common cart for easy transport directly to a site of use.
It is known that different types of cleaning solution are required for proper cleaning of different types of upholstery material. For example, many upholstery materials may be cleaned effectively and easily using a water based cleaning solution, whereas other types of upholstery material may be cleaned according to so-called "dry" cleaning procedures using a nonaqueous solution such as an appropriate petroleum based solvent or the like. Accordingly, to accommodate these different cleaning environments, it is often necessary to change from one type of cleaning solution to another. Unfortunately, aqueous and nonaqueous cleaning solutions are generally incompatible with each other and will tend to form a gelatinized sludge when intermixed. It is therefore necessary for a prior cleaning solution to be purged or flushed from the flow lines and tanks of the cleaning equipment before a different type of cleaning solution can be used. A failure to purge or flush the prior cleaning solution creates a substantial risk of malfunction due to clogged flow lines.
In the past, in recognition of the potential clogging problem, it has been necessary to remove the cleaning tool from its associated flow lines and then perform external interconnection of the solution flow lines and vacuum hose to purge the system components. However, this approach involves a series of manual steps which can be complicated and confusing to many machine operators, such that component purging is often performed improperly or not at all. Moreover, following this prior art approach, residual cleaning solution is not normally removed from the cleaning tool, with the result that the tool can become clogged or a small quantity of the incorrect cleaning solution can be delivered from the tool when cleaning operation is resumed.
There exists, therefore, a significant need for an improved cleaning system of the type including equipment for delivering and vacuuming cleaning solution, wherein the system includes relatively simple and easily operated means for flushing cleaning solution from the components and related flow lines thereby facilitating a change in cleaning solution type. The present invention fulfills these needs and provides further related advantages.